/*

 * Copyright (c) 2002, 2019, Oracle and/or its affiliates. All rights reserved.

 * Copyright (c) 2012, 2018 SAP SE. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#ifndef CPU_PPC_NATIVEINST_PPC_HPP

#define CPU_PPC_NATIVEINST_PPC_HPP

#include "asm/macroAssembler.hpp"

#include "runtime/icache.hpp"

#include "runtime/os.hpp"

#include "runtime/safepointMechanism.hpp"

// We have interfaces for the following instructions:

//

// - NativeInstruction

//   - NativeCall

//   - NativeFarCall

//   - NativeMovConstReg

//   - NativeJump

//   - NativeIllegalInstruction

//   - NativeConditionalFarBranch

//   - NativeCallTrampolineStub

// The base class for different kinds of native instruction abstractions.

// It provides the primitive operations to manipulate code relative to this.

class NativeInstruction {

  friend class Relocation;

 public:

  bool is_jump() { return Assembler::is_b(long_at(0)); } // See NativeGeneralJump.

  bool is_sigtrap_ic_miss_check() {

    assert(UseSIGTRAP, "precondition");

    return MacroAssembler::is_trap_ic_miss_check(long_at(0));

  }

  bool is_sigtrap_null_check() {

    assert(UseSIGTRAP && TrapBasedNullChecks, "precondition");

    return MacroAssembler::is_trap_null_check(long_at(0));

  }

  // We use a special trap for marking a method as not_entrant or zombie

  // iff UseSIGTRAP.

  bool is_sigtrap_zombie_not_entrant() {

    assert(UseSIGTRAP, "precondition");

    return MacroAssembler::is_trap_zombie_not_entrant(long_at(0));

  }

  // We use an illtrap for marking a method as not_entrant or zombie

  // iff !UseSIGTRAP.

  bool is_sigill_zombie_not_entrant() {

    assert(!UseSIGTRAP, "precondition");

    // Work around a C++ compiler bug which changes 'this'.

    return NativeInstruction::is_sigill_zombie_not_entrant_at(addr_at(0));

  }

  static bool is_sigill_zombie_not_entrant_at(address addr);

#ifdef COMPILER2

  // SIGTRAP-based implicit range checks

  bool is_sigtrap_range_check() {

    assert(UseSIGTRAP && TrapBasedRangeChecks, "precondition");

    return MacroAssembler::is_trap_range_check(long_at(0));

  }

#endif

  // 'should not reach here'.

  bool is_sigtrap_should_not_reach_here() {

    return MacroAssembler::is_trap_should_not_reach_here(long_at(0));

  }

  bool is_safepoint_poll() {

    // Is the current instruction a POTENTIAL read access to the polling page?

    // The current arguments of the instruction are not checked!

    if (SafepointMechanism::uses_thread_local_poll() && USE_POLL_BIT_ONLY) {

      int encoding = SafepointMechanism::poll_bit();

      return MacroAssembler::is_tdi(long_at(0), Assembler::traptoGreaterThanUnsigned | Assembler::traptoEqual,

                                    -1, encoding);

    }

    return MacroAssembler::is_load_from_polling_page(long_at(0), NULL);

  }

  address get_stack_bang_address(void *ucontext) {

    // If long_at(0) is not a stack bang, return 0. Otherwise, return

    // banged address.

    return MacroAssembler::get_stack_bang_address(long_at(0), ucontext);

  }

 protected:

  address  addr_at(int offset) const    { return address(this) + offset; }

  int      long_at(int offset) const    { return *(int*)addr_at(offset); }

 public:

  void verify() NOT_DEBUG_RETURN;

};

inline NativeInstruction* nativeInstruction_at(address address) {

  NativeInstruction* inst = (NativeInstruction*)address;

  inst->verify();

  return inst;

}

// The NativeCall is an abstraction for accessing/manipulating call

// instructions. It is used to manipulate inline caches, primitive &

// dll calls, etc.

//

// Sparc distinguishes `NativeCall' and `NativeFarCall'. On PPC64,

// at present, we provide a single class `NativeCall' representing the

// sequence `load_const, mtctr, bctrl' or the sequence 'ld_from_toc,

// mtctr, bctrl'.

class NativeCall: public NativeInstruction {

 public:

  enum ppc_specific_constants {

    load_const_instruction_size                 = 28,

    load_const_from_method_toc_instruction_size = 16,

    instruction_size                            = 16 // Used in shared code for calls with reloc_info.

  };

  static bool is_call_at(address a) {

    return Assembler::is_bl(*(int*)(a));

  }

  static bool is_call_before(address return_address) {

    return NativeCall::is_call_at(return_address - 4);

  }

  address instruction_address() const {

    return addr_at(0);

  }

  address next_instruction_address() const {

    // We have only bl.

    assert(MacroAssembler::is_bl(*(int*)instruction_address()), "Should be bl instruction!");

    return addr_at(4);

  }

  address return_address() const {

    return next_instruction_address();

  }

  address destination() const;

  // The parameter assert_lock disables the assertion during code generation.

  void set_destination_mt_safe(address dest, bool assert_lock = true);

  address get_trampoline();

  void verify_alignment() {} // do nothing on ppc

  void verify() NOT_DEBUG_RETURN;

};

inline NativeCall* nativeCall_at(address instr) {

  NativeCall* call = (NativeCall*)instr;

  call->verify();

  return call;

}

inline NativeCall* nativeCall_before(address return_address) {

  NativeCall* call = NULL;

  if (MacroAssembler::is_bl(*(int*)(return_address - 4)))

    call = (NativeCall*)(return_address - 4);

  call->verify();

  return call;

}

// The NativeFarCall is an abstraction for accessing/manipulating native

// call-anywhere instructions.

// Used to call native methods which may be loaded anywhere in the address

// space, possibly out of reach of a call instruction.

class NativeFarCall: public NativeInstruction {

 public:

  // We use MacroAssembler::bl64_patchable() for implementing a

  // call-anywhere instruction.

  // Checks whether instr points at a NativeFarCall instruction.

  static bool is_far_call_at(address instr) {

    return MacroAssembler::is_bl64_patchable_at(instr);

  }

  // Does the NativeFarCall implementation use a pc-relative encoding

  // of the call destination?

  // Used when relocating code.

  bool is_pcrelative() {

    assert(MacroAssembler::is_bl64_patchable_at((address)this),

           "unexpected call type");

    return MacroAssembler::is_bl64_patchable_pcrelative_at((address)this);

  }

  // Returns the NativeFarCall's destination.

  address destination() const {

    assert(MacroAssembler::is_bl64_patchable_at((address)this),

           "unexpected call type");

    return MacroAssembler::get_dest_of_bl64_patchable_at((address)this);

  }

  // Sets the NativeCall's destination, not necessarily mt-safe.

  // Used when relocating code.

  void set_destination(address dest) {

    // Set new destination (implementation of call may change here).

    assert(MacroAssembler::is_bl64_patchable_at((address)this),

           "unexpected call type");

    MacroAssembler::set_dest_of_bl64_patchable_at((address)this, dest);

  }

  void verify() NOT_DEBUG_RETURN;

};

// Instantiates a NativeFarCall object starting at the given instruction

// address and returns the NativeFarCall object.

inline NativeFarCall* nativeFarCall_at(address instr) {

  NativeFarCall* call = (NativeFarCall*)instr;

  call->verify();

  return call;

}

// An interface for accessing/manipulating native set_oop imm, reg instructions

// (used to manipulate inlined data references, etc.).

class NativeMovConstReg: public NativeInstruction {

 public:

  enum ppc_specific_constants {

    load_const_instruction_size                 = 20,

    load_const_from_method_toc_instruction_size =  8,

    instruction_size                            =  8 // Used in shared code for calls with reloc_info.

  };

  address instruction_address() const {

    return addr_at(0);

  }

  address next_instruction_address() const;

  // (The [set_]data accessor respects oop_type relocs also.)

  intptr_t data() const;

  // Patch the code stream.

  address set_data_plain(intptr_t x, CodeBlob *code);

  // Patch the code stream and oop pool.

  void set_data(intptr_t x);

  // Patch narrow oop constants. Use this also for narrow klass.

  void set_narrow_oop(narrowOop data, CodeBlob *code = NULL);

  void verify() NOT_DEBUG_RETURN;

};

inline NativeMovConstReg* nativeMovConstReg_at(address address) {

  NativeMovConstReg* test = (NativeMovConstReg*)address;

  test->verify();

  return test;

}

// The NativeJump is an abstraction for accessing/manipulating native

// jump-anywhere instructions.

class NativeJump: public NativeInstruction {

 public:

  // We use MacroAssembler::b64_patchable() for implementing a

  // jump-anywhere instruction.

  enum ppc_specific_constants {

    instruction_size = MacroAssembler::b64_patchable_size

  };

  // Checks whether instr points at a NativeJump instruction.

  static bool is_jump_at(address instr) {

    return MacroAssembler::is_b64_patchable_at(instr)

      || (   MacroAssembler::is_load_const_from_method_toc_at(instr)

          && Assembler::is_mtctr(*(int*)(instr + 2 * 4))

          && Assembler::is_bctr(*(int*)(instr + 3 * 4)));

  }

  // Does the NativeJump implementation use a pc-relative encoding

  // of the call destination?

  // Used when relocating code or patching jumps.

  bool is_pcrelative() {

    return MacroAssembler::is_b64_patchable_pcrelative_at((address)this);

  }

  // Returns the NativeJump's destination.

  address jump_destination() const {

    if (MacroAssembler::is_b64_patchable_at((address)this)) {

      return MacroAssembler::get_dest_of_b64_patchable_at((address)this);

    } else if (MacroAssembler::is_load_const_from_method_toc_at((address)this)

               && Assembler::is_mtctr(*(int*)((address)this + 2 * 4))

               && Assembler::is_bctr(*(int*)((address)this + 3 * 4))) {

      return (address)((NativeMovConstReg *)this)->data();

    } else {

      ShouldNotReachHere();

      return NULL;

    }

  }

  // Sets the NativeJump's destination, not necessarily mt-safe.

  // Used when relocating code or patching jumps.

  void set_jump_destination(address dest) {

    // Set new destination (implementation of call may change here).

    if (MacroAssembler::is_b64_patchable_at((address)this)) {

      MacroAssembler::set_dest_of_b64_patchable_at((address)this, dest);

    } else if (MacroAssembler::is_load_const_from_method_toc_at((address)this)

               && Assembler::is_mtctr(*(int*)((address)this + 2 * 4))

               && Assembler::is_bctr(*(int*)((address)this + 3 * 4))) {

      ((NativeMovConstReg *)this)->set_data((intptr_t)dest);

    } else {

      ShouldNotReachHere();

    }

  }

  // MT-safe insertion of native jump at verified method entry

  static void patch_verified_entry(address entry, address verified_entry, address dest);

  void verify() NOT_DEBUG_RETURN;

  static void check_verified_entry_alignment(address entry, address verified_entry) {

    // We just patch one instruction on ppc64, so the jump doesn't have to

    // be aligned. Nothing to do here.

  }

};

// Instantiates a NativeJump object starting at the given instruction

// address and returns the NativeJump object.

inline NativeJump* nativeJump_at(address instr) {

  NativeJump* call = (NativeJump*)instr;

  call->verify();

  return call;

}

// NativeConditionalFarBranch is abstraction for accessing/manipulating

// conditional far branches.

class NativeConditionalFarBranch : public NativeInstruction {

 public:

  static bool is_conditional_far_branch_at(address instr) {

    return MacroAssembler::is_bc_far_at(instr);

  }

  address branch_destination() const {

    return MacroAssembler::get_dest_of_bc_far_at((address)this);

  }

  void set_branch_destination(address dest) {

    MacroAssembler::set_dest_of_bc_far_at((address)this, dest);

  }

};

inline NativeConditionalFarBranch* NativeConditionalFarBranch_at(address address) {

  assert(NativeConditionalFarBranch::is_conditional_far_branch_at(address),

         "must be a conditional far branch");

  return (NativeConditionalFarBranch*)address;

}

// Call trampoline stubs.

class NativeCallTrampolineStub : public NativeInstruction {

 private:

  address encoded_destination_addr() const;

 public:

  address destination(nmethod *nm = NULL) const;

  int destination_toc_offset() const;

  void set_destination(address new_destination);

};

// Note: Other stubs must not begin with this pattern.

inline bool is_NativeCallTrampolineStub_at(address address) {

  int first_instr = *(int*)address;

  // calculate_address_from_global_toc and long form of ld_largeoffset_unchecked begin with addis with target R12

  if (Assembler::is_addis(first_instr) &&

      (Register)(intptr_t)Assembler::inv_rt_field(first_instr) == R12_scratch2) return true;

  // short form of ld_largeoffset_unchecked is ld which is followed by mtctr

  int second_instr = *((int*)address + 1);

  if (Assembler::is_ld(first_instr) &&

      (Register)(intptr_t)Assembler::inv_rt_field(first_instr) == R12_scratch2 &&

      Assembler::is_mtctr(second_instr) &&

      (Register)(intptr_t)Assembler::inv_rs_field(second_instr) == R12_scratch2) return true;

  return false;

}

inline NativeCallTrampolineStub* NativeCallTrampolineStub_at(address address) {

  assert(is_NativeCallTrampolineStub_at(address), "no call trampoline found");

  return (NativeCallTrampolineStub*)address;

}

///////////////////////////////////////////////////////////////////////////////////////////////////

//-------------------------------------

//  N a t i v e G e n e r a l J u m p

//-------------------------------------

// Despite the name, handles only simple branches.

class NativeGeneralJump;

inline NativeGeneralJump* nativeGeneralJump_at(address address);

// Currently only implemented as single unconditional branch.

class NativeGeneralJump: public NativeInstruction {

 public:

  enum PPC64_specific_constants {

    instruction_size = 4

  };

  address instruction_address() const { return addr_at(0); }

  // Creation.

  friend inline NativeGeneralJump* nativeGeneralJump_at(address addr) {

    NativeGeneralJump* jump = (NativeGeneralJump*)(addr);

    DEBUG_ONLY( jump->verify(); )

    return jump;

  }

  // Insertion of native general jump instruction.

  static void insert_unconditional(address code_pos, address entry);

  address jump_destination() const {

    DEBUG_ONLY( verify(); )

    return addr_at(0) + Assembler::inv_li_field(long_at(0));

  }

  void set_jump_destination(address dest) {

    DEBUG_ONLY( verify(); )

    insert_unconditional(addr_at(0), dest);

  }

  static void replace_mt_safe(address instr_addr, address code_buffer);

  void verify() const { guarantee(Assembler::is_b(long_at(0)), "invalid NativeGeneralJump"); }

};

// An interface for accessing/manipulating native load int (load_const32).

class NativeMovRegMem;

inline NativeMovRegMem* nativeMovRegMem_at(address address);

class NativeMovRegMem: public NativeInstruction {

 public:

  enum PPC64_specific_constants {

    instruction_size = 8

  };

  address instruction_address() const { return addr_at(0); }

  intptr_t offset() const {

#ifdef VM_LITTLE_ENDIAN

    short *hi_ptr = (short*)(addr_at(0));

    short *lo_ptr = (short*)(addr_at(4));

#else

    short *hi_ptr = (short*)(addr_at(0) + 2);

    short *lo_ptr = (short*)(addr_at(4) + 2);

#endif

    return ((*hi_ptr) << 16) | ((*lo_ptr) & 0xFFFF);

  }

  void set_offset(intptr_t x) {

#ifdef VM_LITTLE_ENDIAN

    short *hi_ptr = (short*)(addr_at(0));

    short *lo_ptr = (short*)(addr_at(4));

#else

    short *hi_ptr = (short*)(addr_at(0) + 2);

    short *lo_ptr = (short*)(addr_at(4) + 2);

#endif

    *hi_ptr = x >> 16;

    *lo_ptr = x & 0xFFFF;

    ICache::ppc64_flush_icache_bytes(addr_at(0), NativeMovRegMem::instruction_size);

  }

  void add_offset_in_bytes(intptr_t radd_offset) {

    set_offset(offset() + radd_offset);

  }

  void verify() const {

    guarantee(Assembler::is_lis(long_at(0)), "load_const32 1st instr");

    guarantee(Assembler::is_ori(long_at(4)), "load_const32 2nd instr");

  }

 private:

  friend inline NativeMovRegMem* nativeMovRegMem_at(address address) {

    NativeMovRegMem* test = (NativeMovRegMem*)address;

    DEBUG_ONLY( test->verify(); )

    return test;

  }

};

#endif // CPU_PPC_NATIVEINST_PPC_HPP